How to create an installation USB flash drive for iMac from under Windows?

Question

macOS

Good day!
Faced the following problem.
There is an iMac fig-understand-what year (it's fat, that's all I can say about it). It has an OS on it.
When you try to install the OS through Disk Utility, it first asks you to sign in to your Apple ID. Registered, done, everything is ok. Further, at one of the stages, he writes that "This object is temporarily unavailable." At the same time, I tried to do this through cmd+R and option+cmd+R and shift+cmd+R - the result is always the same.
I read that you can create a bootable USB flash drive for a Mac. Well ...
The situation has not changed dramatically (spoiler: the bootloader does not see the USB flash drive)
There is a TransMac. In it, I select "Format Disk for Mac", after that "Restore with Disk Image" and select the previously downloaded torrent from "Install OS X El Capitan.dmg". I wait until it is written, I insert the USB flash drive into the poppy, I select "End Disk Utility" to get a window with the ability to select a bootloader. And there's nothing. Empty.
Tried to do the same with BDU, same result. What could be the reason? How can I do it?

Answer 1

I assume that your iMac hard drive is encrypted (APFS Encrypted). You need to remove all partitions (containers) from the disk before installation. Boot into recovery mode via the Internet - Command + R. Go to Disk Utility, in the upper right corner change the View to show containers, select the parent disk and delete everything (Partition), making one APFS format partition. Next, close Disk Utility and start installing the OS.